Valve-gear.



No. 763,502. PATENTBD JUNE 28, 1904. l

v S. L. MGCAIN-` VALVE GEAR. APPLIGATIONTILED JAN. 4, 1904.

No MODEL. s

-u s Z/ v4,

will l n Inventor Attorney .Witnesses @Q/W' B Maw Y l l Y v PatentedJune 28, 1904.

PATENT OFFICE.

SIDNEY LEA` MCCAIN, OF HUTCHINS, TEXAS.

VALVE- SPECIFICATIONl forming part of riet-'nefs4 Patent No. 763,502,dated June 28, 1904.

Application ned January 4, 1904.

T0 all w/wm t mafyconccrn:

Be it known that I, SIDNEY LEA MCCAIN, a citizen of the United States,residing at Hutchins, in the county of Dallas and State of Texas, haveinvented certain new and useful Improvements in Valve-Gear; and I dodeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same. Y

This invention relates to improvements in valve-gears for steam-engines.

The object of the invention is to provide a valve-gear for engines whichwill be simple, strong and durable in construction, eliicient in action,and inexpensive of production.-

VVith this and other objects in'view the inventioniconsists of certainnovel features of construction,` combination, and arrangement of parts,as will be more fully described, and particularlyT pointed out in theappended claim.

In the accompanying drawings, Figure 1 is a side elevation of an engineconstructed in accordance with the invention. Fig. 2 is a verticallongitudinal sectional view taken through the piston-chamber andsteam-chest. Fig. 3 is a vertical transverse sectional view through thecylinder-casing on a line with one of the valve-chambers. Fig. 4 is asimilar view taken on a line with the inlet and exhaust pipes. Figs. 5and 6 are detail views of opposite sides of the plug-valves.

Referring more particularly to the drawings, 1 denotes thecylinder-casing. 2 denotes the steam chamber or chest arranged in theupper part of said casing. `3 denotes the exhaust-chamber arranged inthe rear portion of the casing, as shown.

4 denotes the steam-supply pipe which communicates with thesteam-chamber 2, .and 5 denotes the exhaust-pipe which communicates withthe exhaust-chamber.

Below the steam chamber or chest is arranged the piston chamber orcylinder 6, closed at its ends by heads 7. In the cylinder is mountedthe piston 8, having the usual pistonrod 9, which works through astuing-box 10 in the front head 7 of the cylinder in the usual manner.

Serial No. 187,699. (No model.)

In the casingl between the cylinder and the steam-chamber arehorizontally-disposed transversely-arranged valve-chambers 12 and 13,which extend into the casing and communicat'e at their rear ends withthe exhaustchamber 3. The valve-chambers 12 and 13 are arranged aboveeach `end of the piston chamber or cylinder and are in communicationtherewith through ports 14. The valve-chambers are also in communicationwith the steamchamber 2 by portsl, which are immediately above or inline with the ports 14.

Within the valve-chambers 12 and 13 are ararranged rotary plug-valves16, which are held in place in said chambers by cap-plates 17, on

which are formed stuffing-boxes 18, through which pass the stems 19 ofsaid valves. In one side of each of the plug-valves is formed asegmental or semi-annular groove or channel 20, and on the opposite sideof each valve is formed a longitudinally-disposed groove or channel 21which extends to the ends of the same and communicates with thedischarge-chamber 3 at the rear. W'hen the plug-valves are turned to acertain position,these grooves 21 will also communicate with thecylinder-ports 14,`thereby forming a passage'between the cylinder orpiston-ch amber and the exh aust-chamber through which steam may beexhausted at the proper time. The valves are also adapted to be turnedto bring the grooves 20 into such a position that the opposite endsofthe same, communicate with the cylinder-ports 14 and the ports '15 inthe steam chamber or chest 2, and thereby forming an inlet-passage tothe cylinder or piston-chamber. On the stems 19 of the valves aresecured crank-arms 22, to which are adjustably connected link-rods 23,the opposite ends of which are pivotally connected to the lower side ofa wrist-plate 24, pivoted on the side' of the casing 1. To the upperside of the wrist-plate is pivotally connected a reach-rod 25, theopposite end of which is pivotally connected to the upper end of apivoted rocker-arm 26, the lower-end of which is connected to aneccentric-rod 27, which extends from the usual eccentric disk 'on thecrank-shaft. (Not shown.) vWhen the crankshaft is turned, motion will bcimparted through said eccentric-rod to the rocker-arm IOO and reach-rodand to the wrist-plate 24, which will oscillate the valves to cause thechannels l or passages in the same to alternately afford communicationbetween the exhaust and steam chambers and the piston-chamber atopposite ends of the same, as will be understood. The piston-rod 9 ofthe piston 8 extends through a stuing-box in the head of said cylinderin the usual manner. The end of the piston-rod is connected to across-head 30, which is slidably mounted in guideways 31, and to the endof said piston-rod or to said cross-head is connected a pitman-rod 32,the opposite end of which is connected to the crank-shaft (not shown) inthe usual or any suitable manner.

From the foregoing' description, taken in connection with theaccompanying drawings, the construction and operation of the inventionwill be readily understood without requiring a more extendedexplanation.

Various changes in the form, proportion, and the minor details ofconstruction may be resorted to without departing from the principle orsacrificing any of the advantages of this invention.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

In a valve-gear for engines, a cylinder-casing provided with apiston-chamber', a steamchamber in parallel relation therewith, anexhaust-chamber arranged in rear of and on a line between said pistonand steam chambers, valvechambers extending longitudinally from thefront of the casing transversely of and between the piston and steamchambers and communicating at their rear ends with said exhaust chamber,and ports connecting the valve-chambers with the steam-chamber andopposite ends ofthe piston-chamber, in combination with oscillatingplug-valves arranged in said valve-chambers, each of' said valves havingin one side asemi-annular groove to connect the piston-chamber with thesteamchamber when the valve is in one position and in its opposite sidea longitudinal groove to connect the piston-chamber with theexhaustchamber when said valve is in a different position, and'means foroscillating the valves to alternately govern the supply and exhaust ofsteam, substantially as described.

In testimony Whereot` I have hereunto set my hand in presence-of twosubscribing witnesses.

SIDNEY LEA MCCAIN.

Witnesses:

' CLYDE MCCURDY,

C. R. REA.

